Main characteristics of a frame relay network are that an asynchronous multiplexing technology based on a variable-length frame is adopted and a transmission rate of a data service packet is high. When a service packet which is of voice, video and so on and is sensitive to delay time (hereinafter abbreviated as sensitive service packet) and a data service packet are transmitted mixedly, the two kinds of service packets competes. If the data service packet is transmitted preferentially, and the data service packet is relatively long (such as a jumbo frame), the sensitive service packet needs to wait to be sent until the data service packet is completely sent, and waiting time (which is generally 8 ms) cannot be accepted for the sensitive service packet, which leads to a jitter of the sensitive service packet.
In the prior art, a method for reducing a jitter of a sensitive service packet in a frame relay network is put forward: when a sensitive service packet and a data service packet are transmitted mixedly, first slice the data service packet, that is, divide the data service packet into multiple segments according to a specified length, and then, enable the sensitive service packet to compete with slices. Because a length of a slice is relatively short, even if the slice is transmitted preferentially, waiting time of the sensitive service packet is also greatly shortened, thereby achieving an objective of reducing the jitter of the sensitive service packet.
However, in the foregoing method for reducing the jitter of the sensitive service packet, multilink point-to-point protocol (MLPPP) encapsulation needs to be performed on each slice of the data service packet before each slice of the data service packet is sent, so that an 11-byte encapsulation overhead is averagely increased for each slice; when the data service packet is transmitted through a physical port on a sending/receiving apparatus, a bandwidth utilization rate of a communication link is significantly decreased, which causes that the method for reducing the jitter of the sensitive service packet cannot be used in the microwave communication field which has a relatively high requirement for the bandwidth utilization rate.